Segmenting Boiling Water Reactor Control Rod Splines
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Solution Overview
Problem
Boiling water reactor control rod blades pose challenges in storage and disposal due to their size, configuration, embrittlement, and radiological activity, with existing segmentation methods being inefficient and potentially hazardous, especially in releasing radioactive gases and debris.
Innovation Solution
A double bladed band saw apparatus that vertically severs the control rod spline into four equal sections along the central axis without cutting through the blade panels, using a tool base plate with pulley wheels and band saw blades to minimize radioactive material release and facilitate efficient storage and transportation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If control rod blades are segmented vertically along the central spline, then storage volume is reduced and handling is simplified, but radioactive gases may be released from neutron absorber rods
Solution Approach 1:
The control rod blade is segmented vertically into multiple sections along the central spline using a band saw apparatus. The blade is divided into upper, middle, and lower sections without cutting through the blade panels themselves, reducing storage volume while maintaining containment of radioactive materials within each segment.
Solution Approach 2:
The cutting operation is localized to specific regions - only the central spline is cut, not the entire blade structure. The blade panels are preserved intact in each segment, maintaining local containment properties while achieving overall volume reduction through selective segmentation of the spline region.
2Manufacturing precision
If multiple sequential cuts are made to segment control rod blades, then segmentation precision can be maintained, but cutting time and handling complexity increase
Solution Approach 1:
Multiple cutting operations are merged into a single continuous band sawing process. The band saw apparatus makes multiple vertical cuts along the central spline in one continuous operation, dividing the blade into multiple sections simultaneously rather than requiring separate positioning and cutting for each segment.
Solution Approach 2:
The band saw operates continuously along the length of the control rod blade, maintaining constant cutting action without interruption. The apparatus moves smoothly along the spline, making all necessary cuts in one continuous pass, eliminating the need to stop, reposition, and restart between cuts.
3Ease of operation
If control rod blades are cut into shorter segments, then handling and storage becomes easier, but the number of cuts and handling operations increases
Solution Approach 1:
The control rod blade is divided into a reasonable number of manageable segments (typically three: upper, middle, and lower sections) rather than excessive fragmentation. This segmentation level provides optimal balance between handling ease and operational complexity, creating segments small enough for manageable storage but not so small that excessive cuts are required.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The apparatus significantly reduces storage volume, minimizes radioactive debris release, and simplifies handling and transportation by creating manageable segments with precise cuts, reducing cutting and handling times while maintaining the integrity of neutron absorber materials.
Implementation Method 1
a drive wheel that is operatively connected to a motor to rotate the drive wheel when the motor is in an on state
Data Source
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AI summary
Apparatus for longitudinally segmenting a cruciform shaped irradiated boiling water reactor control rod having four elongated blades radially extending from a central spline, into four flat panels. The apparatus employs a double bladed band saw with the band saw blades orthogonally oriented at two different elevations and having one side of each band saw blade crossing over the center of the spline of the control rod in between the control rod blades.